Moisture tester



Dec. 23, 1952 H. l.. CAMPBELL MOISTURE TESTER 2 SHEETS-SHEET l Filed April l, 1950 Dec. 23, 1952 H. 1 CAMPBELL MOISTURE TESTER Filed April l, 1950 2 sHEETsh-SHEET 2 u@ Og@ Patented Dec. 23, 1952 inermi-.0 A

ciad addon; Drat on of Illinois` y aioi's'rnnn 'resiente i Oak Par."

Company; Chicago, Ill., a cor- This invention relatesfto moisture tester, and` more partieui'a'rly to suoli device struetedv andfar'range'. that lie Y to loe tested is Aueigliedand vE irieoinici.the amount of moisture" driven off isga'fter suitalle manipulation of a registering' dfviei read oit directlyin percentage" of suel'i rfoi" s"tuie.` iniportant feature l Dfit"1le1jltiO iftYle use of a counter-Weight totalen'ee the major loads, and a flexible cha' 'or the like'toija'lane the variable minor' loads Within the'l range of the apparatus, and" tlief uabilityJL toA reati,M the amounts' oi moisture drivenu oii".directlyN in percentages; l

TheV original and standard' termining the amount ofl moisturefin' granular materials, as practiced prior to'vthepresfent: invention, was to Weigh'out finite'agiount of sample on accurate balance, put the 'r'npl'e in an oven heated to a pr'eseribed; te u'fperatnrey for a sufcient length ottime tore'i v'eftl'e moisture, then cool outer co ,"1' st air, and'vweigh again on a" accurate "f compute lthe"per'eentagel by'calcul tion. l In'v the' oid practice, if' the saip'le were ridi e'bied out of centact with' moist air?beforel the"second Weighing, some moisture'would41 have" oefenn taken upV by' the sample from'tie" airfbefause of the time consuming procedu e required With the moisture tester'loff'tt p vention,4 thevr procedure is'fsomuoh Ifore'fsimple'v and rap'id'th'at the iinal` reading of thelpe-Y centage' of moisture driven oiflcn bedireetly read almost instantly AafterftleJ moisture has" been' driven on from thev sample', thuselin'iiatingthe danger of adsorptionof' moisture lo'ytlieA sample due to lapse of time, and providing a tester thatis foolproof, can bel carried" from` place 'to place Where' electricityis available, and operated by unskilledhelp' toobtainhuick andl accurate'results. y l

Among the objectsof"thevpresent invention are z' to'provde a moisture tester thatf-Qwill'overcome the disadvantages, and 'acico'i,nplislV theV afil-v vantag'es, referred to earlier herein to provide a'novel and improved` moisture'tester to'pr'c'iv vide' a moisture tester in which'the"s'ampleot moistgranular material may be'weig'led on the' moisture driven off may-v life"quickly','and easily read directly in` peicentageo'f moisture 'reinved;I

dried, and the 'perc'etagleuof remo'v I moisture directly read, While thev sample remainsnplaee Si of. moisture removed; top prvide. f1

means ei'varying' the effective rfvieigfit of a chain ture" removed in, percentages`;` tollproide new means'for dryingthe moist material ontli'e teSt-j egl; t0 provide a' moisture tester thatwllduickly produce aceurate results Withlan vunskilled p;- erator; to enclose the balance-Landau c' l 15a s'f'witl'iinacabinet to enable, thetes f bei safely us'dlin vany part of the .plant orsnbp by unskilled labor; and such furthertobjectfs. advantages, c aan' ,eapabninea inherently pose ses/Sed 'by' invention; as Will later more" fully appear. i .v A My invention further residesfijn thecomb` tion, VAconstruction and` arrangement lof v parts' il-y lustrate'd in. the acc'ornpaIl'ying' drawings, and While, I have shown therein Aav prefer'r`eijlfl emr bodiment`, Wisch it understoodthatV tlie'.v saine is, susceptible of modification and ,changefwithout departing frointhe spirit of my invention.

In the drawings: f ,t V1.- Fig; lis a longitudinal, verticalseeton`ftal en on a median plane, of ',Inyimproved moisture tester, parts being shown' in.' elevati'orifor conv'e'nien'ce andbetter understanding, and 'showing the 4pan containing a sample' ready for' drying anaitestin'g. l Fig. 2"is` a front elevation looking towardthe left haiidsde of Figi Y, i Fig. 3 is afragmenty lOn gitlidin'al,-veitcall section, some of the' interiorjyparts loleinggoiijnt d. forii conv'en'ienee;` and snowing thev ,sample pan:V empty,- andthe heater' lamp swung'toone side" auayfrom'ythe pan. Y. Y) IFigi. r4l is ai traginentary,Y fronti elevation' look'g. ing'lt "rd the-.front panel. Window; .through wiiieh the readings' are read, ,andlgszriowirietiie pointerof'tne balance inthe 'positionshoivn' Fraai ,A Y. Figi' 5l isaffraghentary,Vertical section ontiie unes--tbfFig.3.-` l I l, Fi'g` is a fragin/entary,y perspe.c'tiye'deta showingma 'smallprtionof the lm'earis vfor ,r' ingf and,lotveringftheflible ,chaire and` the, netiolrither'ewith @finie low" einer th ible,` chain," forf` different increments of showing a small portion of the front end of the balance beam with the pointer member fixe-d thereto for movement upwardly and downwardly therewith.

In the form shown in the drawings, for illustrative purposes, my invention comprises in general, a cabinet I having top, bottom and side Walls, a balance 2 mounted upon a support 3 spaced upwardly a suitable distance from the cabinet bottom wall by rods, columns or the like 4 of which any suitable number (preferably four) may be used as desired, a supporting plate 5 for receiving a pan 6 for sample material to be tested, a heat radiating lamp i swingably mounted on the cabinet top wall, a transparent disk 8 having around its marginal edge graduations 9 and at a distance inside of said marginal edge a concentric circle Il), and a shaft II journaled adjacent its ends in the cabinet front and rear walls, said shaft at its rear end having means I2 for raising and lowering the lower end of a flexible chain I3, said chain at its opposite end being connected with the rear end of the balance beam I4.

The balance 2 is merely shown diagrammatically, and while it may be of any suitable type, I prefer to use a torsion balance of a conventional type available commercially on the market. As no claims are made to the speciiic construction of the balance per se, other than its connection with the other parts of the present combination, it is deemed suiiicient to show it more or less diagrammatically, for the purpose of the present application. One form of such torsion balance is available on the market as a regular commercial product of The Torsion Balance Company. Hence it will be hereinafter referred to generally as a balance, which is tiltably mounted on the support 3. Suitably articulated with balance 2, and extending upwardly therefrom through an opening I5 in the top wall of the cabinet to have free vertical movement therethrough as the balance is moved in one direction or the other during its operation, is a stem I5 having mounted on its upper end a horizontal supporting plate 5. Plate 5, at suitable intervals around its circumference, is formed with upstanding outwardly flared ears Il of any suitable number, so that the pan 6 may be remov ably seated on plate 5 when desired.

Extending upwardly from the cabinet top wall, at a suitable distance to the rear of the pan plate 5, and preferably about midway of the width of the top wall, is a column I8 which may be either stationary or axially rotatable with relation to the cabinet top wall as desired. In Fig. 3 it has been shown as rotated through 90 with relation to the position shown in Fig. 1. Rotatably mounted on the top of column I8, or xed thereto if the column is rotatable, is a cap member I9 having iixed thereto to extend laterally therefrom a tubular arm 2i) to the outer end of which is fixed a downwardly extending socket member 2I, into which is removably screwed the heat radiating lamp 1. The length of arm is such that the vertical central axis of lamp 1, approximately passes through the center of pan 6 when swung thereover. This positions the bottom face of the lamp substantially centrally over the contents of the pan, which bottom face is positioned slightly above the top of the material in the pan so as to clear the same when swung thereover or away therefrom, and to give effective heat radiation to the pan and its contents. Heat bulb 1 may be of 4 any suitable conventional type obtainable on the market, and which is so constructed as to direct the heat rays through the bottom of the bulb, as viewed in Fig. 1, directly toward the pan and its contents. While I do not wish to be limited thereto, I have had successful results with an infrared heat bulb of 250 watts and volts.

Electric current is supplied to the bulb through wires in a cord 22, which passes through the hollow interior of cap member I9, tubular arm 20, and to the interior of socket member 2 I. A conventional automatic timing switch 23 is provided, which may be mounted on the column I8, or on any other suitable location on the cabinet, and which may be set in the usual manner for turning oli the current to the bulb at the end of the time for which it may be set. As such automatic timing switches may be purchased on the market, it will be unnecessary to describe the same in greater detail, further than to state that the electric cord 22 leads into the timing switch, and connected with the switch is a supply cord 24, of any desired length, and provided at its free end with a plug 25 for connection with any convenient wall socket carrying a source of electricity. It is thus seen that the heat bulb may be swung over, and away from, the pan and its contents as desired, and the timing switch may be set to automatically cut off the current to the bulb after any length 0f time desired.

Shaft II extends a slight distance beyond the front wall of the cabinet and has xed to said extending end a knob 26, which when rotated will rotate this shaft. Likewise, just inside the cabinet front wall, the disk 8 is fixed to shaft II to rotate therewith upon rotation of knob 2t. Disk 8 is formed of a transparent material, such as glass, a transparent commercial plastic material, or the like, around the marginal edge of which are provided said graduations 9. Formed in the upper portion of the cabinet front Wall is an opening 27, having an upper edge curved concentrically with disk 8, and provided with a strip 28 whose lower face is beveled outwardly and upwardly, and whose inner lower edge is approximately in registry with the outer edge of disk 8, as seen in Figs. 1 and 3. In order to prevent entry of dust into the cabinet, opening 2 is provided with a transparent window 29 of glass, commercial plastic material, or other suitable transparent material. Through window 29 the graduations 9 on disk 8 may be read, when the disk is rotated to present such graduations behind the window.

Fixed in, or on, the center of the lower face of beveled strip 28, to fall in the vertical center line passing through the center of knob 26, is an index line :it the lower end of which is approximately on the level of, and close to, the marginal edge of disk 8, to serve as a marker for the graduations on the disk when reading the results of the operation of the tester. Also fixed on the disk 8, at a predetermined distance radially inwardly from the graduations 9, is the circular line I0, which is concentric with the axis of shaft II. Depending from the front end of the balance beam I4, and fixed thereto, is a wire 3| (see Fig. 7) the bottom end portion of which is bent at right angles forwardly and to the front end of which is fixed a lateral pointer wire 32, curved on a radius equal to that of the circle Io, to indicate the points of balance when the pointer 32 coincides with circle I0. As stated, the graduations are observed through the window 29.

Fixed to the rear end portion of shaft II to Maa-,4:38

rotate therewith, adjacent the' cizabirret rear wall, is a sprocket wheel 33, and journaled to the'rear Wall above Aand below Wheel 33, are the smaller top and` bottom sprocket wheels 34'and35; respectively (see Fig. 5). Running1 over the teeth of the sprocket'wheels `33-35 isa sprocket chain 36 to be moved as the shaft II- rotates-mene direction` or the other. Extending laterally- 'from a predetermined oneof the links of-sprocket chain 36 isa p in 31 (see Figs. -1 andbf); to-theouter end-,owhich is connected the lower end-offsaid small flexible chain I3, which, as-sta'ted herein, isconnected at its upper end-'withthe-rear end 'or balance beam I4.

Removably mounted on the rear portion ofv the balance, at a predetermined point, is acounterw'eilght 38e'. For illustrative purposesli'n thefte'ster. apparatus described herein, certain values have been given, but it will be understood that the values and proportions.may be 'changed'in differenti machines withoutv departing;A from the spirit of the invention, the main requirementbeingthat. the g'raduations 9 represent. percentages of. mois.- ture driven oi. In the machine describedherein,

the: counter-weight ifis 42.5; grams, the .effective maximum weight or thev ilexible chain I3' is.'7.5V

grams, andthe weight of the moist material placedinthe pan. at theA beginningof the test is 50n grams. With these va-luesthev parts, areI so proportioned that, with the counter-weight in I.

place, 4with 50 grams Vof'moist material in thepan, andjvith the flexible, chain I-3 in itslowermost positiom thepointer 3| willbein registry with thev top of circle Iii` as seen in Fig'. 2', Also` withv these. conditions theo of thegraduations 9- will be in registry with the index line Sifbecause of rotation ot knob 2e and shaft II to bring the flexible chain I Lito its lowered position.

When vthefknob 25- is-rotated to bring-'the o of heat from the bulb enters the moist material inv the pan, and Aalso heats ythe pan which'conductsvv the heat to the bottom of the mass of material, thus driving the moisture out of the material and drying it. After a period of three-minutes the current is automatically turned off. During this drying'operation the moisture drivenofi from the material has correspondingly lessened the weight of the material, which causes thepointer 32 to rise to a higher level as indicated by the dotted lines 32 in Fig. 2. The knob 26 is then 'turned counter-clockwise which progressively raises-the lower endof the flexible chain` I3 .and correspondingly lessens the weighton the rear end-of the balance. This is continued until-i the pointer 32 descends into registry .with theftop of the circle I0, and the value of the graduation in line with the index-line Se is then read; This indicates the percentage ofv moisture that was driven joffofrom the material inbringing it to ad'ry condition.

While a sprocket chain and sprocket wheels, driven by rotation of shaft Il, have been shown and described herein for illustrative purposes, it will be understood that other means rotated by shaft II may be utilized for decreasing and increasing the eiective length of ilexible chain I3, Without departing from the spirit of the invention. When the marking on the dial of disk 8 is in registry'with index line 30', the balance` is weighted with the counterweight 38r andthe maxi-mum Weight of the iiexible` chain I3. IIhe counterweig-ht 38 is iixed in amount, but the ef'- Iective weight of cha-in I3 withv relation to the bala-nce Varies Withthe rotation ofv Shaft' I--I because of the rai-si'ngfandloweringof theefreeend of chain I3;

While other types of bal-ance may be used; a tor-sion lrnalance-is-preferre iI because it is rug-ged andi-has noknife edges or delicate bearings. The variations i-nthe balancing load are readily ob;- tainedl by the raising and lowering of: the free end of the flexible chainy I3.,a's the result ofwhichf different increments` of load. can be applied at Willito thebalance by rotation of the` knob 26 and shaftk I I.. Thedial. di'skis calibrated according to. the. increment` of. weight. onV the balance. or indirectly von the length; of chain. I3;` which;4 is effective.. in varying, the weight on `the balance. Atthe 0 position on therdial the `maximum weight of the chain is :applied to the beam of the balance; By turning the knob 4counterclockwise the length of the; chain is shortened, which is equiva1ent=--to decreasingv the applied weight.

The cabinet which'encloses the torsion balance and variable weightv mechanism is entirely enclosedy except around the-stem of the balance pan, thus protecting the 'inner parts against-dustand dirt. The-only parts which can be handledfrom thev outside are the knob,l the `balance pan and the heating fixture. lThe dial is ordinarily vcalibrated for samples weighing 50 grams.t `Formore bulky materialsithe dial could be calibrated for smaller initiall weights. Furthermore, by using a lighter chain, the dial could be calibratedfor lower maximum moisture percentages vand consequentlyrnore accurate readings. Byproviding rapid heating and quick Weighing, only a Very short time is neededto-obtain results.

While the present. apparatus is especially. adapted for the rapid and.. accurate. determination of moisture in yfoundry sands, it may be used for determiningtheaznount ofnioisture in other granular materials.

Having described the invention, 'I claim:`

1. A moisture tester `for. ascertaining theamount of moisture in a given amount of material being tested, comprising, a, cabinet having front, rear, top and bottom walls, a balance/.beam in said cabinet extending in a. directionfrom near the-rear -wall toneartheffrontwall, a stem articulated with the-balance beam'l andi-extending upwardly through the top walliorvfree movement therethrough between-the fulcrum'of the balance beam and the-frontwall, apanonsaid stem' forholding Vthe-material to be tested, a constant counterweighton l the other sidel .or the fulcrum `to balance the':major load, airotatable shaft extending between `therear walll andfront Wall and underneaththe lbalance beam, -a-circular disk xed to.rotate withy said-shaft Vand positioned: closely inside of-the front wall there being moisturepercentage graduations around the-outeredge of -sai :l'disk,1a window iir-the front wall through whichI said `graduations may be` successively read, a pointeron thefront-end ofthe balance beam, there being a concentric mark on the disk to indicate even balance when the pointer and concentric mark are in registry, a chain counterweight having one end fastened to the beam on the same end thereof as is said constant counterweight, and means operated by the shaft and connected with the chain for varying its eifect upon rotation of the shaft, whereby the percentage of moisture dried out of the material being tested may be read on said graduations when the shaft has been rotated to bring the pointer and concentric mark into registry.

2. A moisture tester for ascertaining the amount of moisture removed by drying from a given amount of material being tested, comprising, a cabinet having front, rear and top Walls, a balance beam in said cabinet and having a pointer on its front end adjacent the front wall, a window in the front wall adjacent said pointer, a sample pan above the top wall and supported on the front portion of the balance beam, a constant counterweight on the rear portion of the balance beam, a flexible chain fastened at one end to the balance beam on the same side as the counterweight, a shaft rotatably mounted in the front and rear walls and positioned below the balance beam, means operated by the shaft and connected to the flexible chain to raise and lower the opposite end thereof to vary the effective pull of the chain on the balance beam, a knob on the front end of the shaft outside of the front wall for rotating the shaft, a transparent circular disk fixed to the shaft to rotate therewith inside of the front wall, there being moisture-percentage graduations around the outer edge portion of the disk, an index line in the upper edge of said window, and there being a concentric mark on the disk, whereby when the pan contains a moist sample the pointer will register with the concentric mark, and when the sample has been dried the pointer will be above the concentric mark, and when the knob and shaft have been rotated to return the pointer into registry with the concentric mark, the graduation value on the disk in registry with the index line will represent the percentage moisture removed from the material by drying.

3. A moisture tester for ascertaining the amount of moisture removed by drying from a given amount of material being tested, comprising, a cabinet having front, rear and top walls, a balance beam extending from near the rear wall to near the front wall, a pointer on the front end of the balance beam, the front wall having a window opposite said pointer, an index line in the edge of the window, a sample pan above the top wall mounted on one side of the balance beam, a counterweight on the other side of the balance beam, a shaft below the balance beam and rotatably mounted in the rear and front walls, a light weight flexible chain secured at one end to the rear end of the balance beam and having a depending opposite end, a transparent disk fixed to said shaft adjacent the front wall, there being graduations on the edge portions of the disk, there being a mark on the disk concentric with the shaft, a manually operable knob on the front end of the shaft for rotating the shaft, and means on the rear end of the shaft and connected with the depending end of the chain for varying the weight of the chain on the balance beam, the pointer being above the concentric mark after the material has been dried, and rotation of the shaft will bring the pointer into registry with the concentric mark 8 and the index line will register on said gradua tions the percent of moisture removed from the material sample.

4. A moisture tester as claimed in claim 3, in which said shaft extends beyond both ends of the balance beam and is parallel with the balance beam when the balance beam is in balanced position.

5. A moisture tester as claimed in claim 4, in which said means on the rear end of the shaft includes a sprocket wheel fixed to the shaft, and a sprocket chain running over said sprocket wheel and a smaller sprocket wheel journalled on the rear wall of the cabinet, the light weight flexible chain at its end removed from the balance beam being connected with the sprocket chain to be moved up and down therewith as the shaft is selectively rotated in one direction and the other.

6. A moisture tester for ascertaining the amount of moisture removed by drying from a given amount of material being tested, comprising, a cabinet having front, rear and top walls, a balance beam positioned between the front and rear walls and below the top wall, a sample pan above the top wall and mounted to and on one side of the balance beam, a, counterweight and a light flexible chain mounted to and on the other side of the balance beam, the flexible chain depending from the beam, a shaft rotatably journalled in the front and rear Walls, a knob on the front end of the shaft outside of the front wall, a transparent disk xed to the shaft inside of the cabinet and having graduations on its outer edge portion, a pointer on the front end of the beam, there being a concentric mark on the disk, the beam being in balance with the pointer in registry with the concentric mark when a moist sample is in the pan, a pair of vertically spaced driven sprocket wheels rotatably mounted on the rear wall, a driving sprocket wheel fixed to the shaft to rotate therewith between said pair of sprocket wheels, a sprocket chain in driving engagement with said sprocket Wheels, and the depending end of the first mentioned chain being fixed to the sprocket chain to move therewith when the shaft is rotated, to bring the pointer and concentric mark into registry when the sample is dry, whereby the amount of moisture removed from the sample may be read on the disk graduations.

HARRY L. CAMPBELL.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 262,907 Roedery Aug. 15, 1882 1,089,826 Emerson Mar. 10, 1914 1,258,009 Jacobs Mar. 5, 1918 2,373,056 Seederer Apr. 3. 1945 FOREIGN PATENTS Number Country Date 604,863 Great Britain July 12, 1948 700,167 France Dec. 22, 1930 

